Can’t activate Exchange Server – Use this Exchange Powershell command to activate your Exchange Server

I recently had an issue where through ECP I was unable to activate a new Exchange server 2019 I was building. I believe my issue may have been I was logged into the ECP of an older Exchange (2016) server as the 2019 server’s ECP wasn’t yet accessible.

In any case, you can use this command to activate Exchange servers from the Exchange Powershell:

Set-ExchangeServer -Identity MyNewExchangeServer -ProductKey 12345-12345-12345-12345-12345

Once this has been successfully issued, you will need to restart the Microsoft Exchange Information Store service.